i_cfb64.c

/* crypto/idea/i_cfb64.c *//* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */#include <openssl/idea.h>#include "idea_lcl.h"/* The input and output encrypted as though 64bit cfb mode is being * used. The extra state information to record how much of the * 64bit block we have used is contained in *num; */void idea_cfb64_encrypt(constunsignedchar *in, unsignedchar *out,
long length, IDEA_KEY_SCHEDULE *schedule,
unsignedchar *ivec, int *num, int encrypt)
{
registerunsignedlong v0,v1,t;
registerint n= *num;
registerlong l=length;
unsignedlong ti[2];
unsignedchar *iv,c,cc;
iv=(unsignedchar *)ivec;
if (encrypt)
{
while (l--)
{
if (n == 0)
{
n2l(iv,v0); ti[0]=v0;
n2l(iv,v1); ti[1]=v1;
idea_encrypt((unsignedlong *)ti,schedule);
iv=(unsignedchar *)ivec;
t=ti[0]; l2n(t,iv);
t=ti[1]; l2n(t,iv);
iv=(unsignedchar *)ivec;
}
c= *(in++)^iv[n];
*(out++)=c;
iv[n]=c;
n=(n+1)&0x07;
}
}
else
{
while (l--)
{
if (n == 0)
{
n2l(iv,v0); ti[0]=v0;
n2l(iv,v1); ti[1]=v1;
idea_encrypt((unsignedlong *)ti,schedule);
iv=(unsignedchar *)ivec;
t=ti[0]; l2n(t,iv);
t=ti[1]; l2n(t,iv);
iv=(unsignedchar *)ivec;
}
cc= *(in++);
c=iv[n];
iv[n]=cc;
*(out++)=c^cc;
n=(n+1)&0x07;
}
}
v0=v1=ti[0]=ti[1]=t=c=cc=0;
*num=n;
}